A test method is known, in which a contact probe is brought into contact with an electrode pad of an object to be measured such as a semiconductor wafer or a semiconductor device, and then electricity is input to and output from the electrode pad to evaluate the electrical characteristic of the object to be measured. In recent years, in response to demands for high current and high voltage application of the electricity to be input to and output from the electrode pad, the number of pins of the contact probes has been increased.
However, due to the increased pins, a partial electric discharge phenomenon may occur, for example, between a contact probe and an object to be measured or between the contact probes during evaluation of the object to be measured. This phenomenon causes partial damage or malfunction of the object to be measured in some cases. If occurrence of a partial electric discharge is overlooked and the measured object with damage or the like caused by a partial electric discharge is sent to a subsequent process as a non-defective product, finding the measured object is extremely difficult in the subsequent process. Hence, techniques to restrain the partial electric discharge during the evaluation of the measured object are demanded.
For example, Patent Documents 1 and 2 propose techniques to restrain the partial electric discharge. Further, in recent years, failure analyses are proposed in which damage or the like is detected on the upper or lower surface of the object to be measured during the electrical evaluation by use of the OBIRCH method using infrared radiation to metal, the photo emission microscopic method using light emission detection, an infrared spectroscopic technique, or other methods (for example, Patent Documents 3 and 4).